Mounting for turbine-buckets



A. I. MSLEY. MOUNTING FOR TURBINE BUCKETS- APPLICATION FILED JUNE 25, 1918.

1,345,678 Patented Jul 69 1m lid till

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Specification of Letters l atent.

Patented July e, iaao,

Application can. an 25, ieia terial No. arises.

resident of Philadelphia, in the county of Philadelphia and State of Pennsylyania, have made a new and use'lul TIIVBlltlOlilll ltlounting tor Turbine-Buckets, oi which a the following is a specification.

This invention relates to turbine buckets and particularly to that, class of turb ne buckets used in steam turbines wherein a series of impulse or reaction buckets are mounted in a row upon a turbine rotor.

This invention has for its principal objects the production of a rotor andbucket construction for turbines wherein the buckets may be readily applied and removed from the motor; the production of an improved structure for attaching the bucket shanks to a rotor rim so that they can be applied to the rim substantially from the side thereof; and the production of a simple, inexpensive and eflicient mounting for the buckets and such other objects as may here- Certain embodiments of the invention are illustrated in the accompanying drawings, wherein Figure 1 is a side elevation of the side of the turbine rotor showing the bucket mount Ling.

Fig. 2 is an enlarged section on the line Ill-TT of Fig. 1 and Fig. 3, is a similar section of a modified :lorm of rotor and buckets.

lteferring to the drawings: l is a turbine rotor having a rim 5 carrying a pair of peripheral flanges 6 and 7 spaced apart so as to provide a bucket groove 8 between them.

The bucket retaining flange 6 is of greater height from the bottom of the groove 8 to the periphery oi. the flange than. the depth oi the flange 7, and is provided with an annular overhanging projection 9 which serves to prevent displacement of the radially disposedbuckets 10. a a

The bucket 10 isprovided with a shank 1.19 havinga projection 12 at its lower end t which is adapted to it under the projecting ridge 9 so that it will be held firmly against the action of centrifugal force tench ing to throw the bucket from the rotor. The underside of the ridge or projection 59 is preferably disposed at right angles to the inner face oi the flange 6, which construction provides a secure locking connection betweeen the bucket shank l1 and the rotor.

Referring to Fig. 2, it will be seen that the enlarged end of the shank 11 is of less width than the narrowest opening in the groove 8 and that the bucket shank 11 may be inserted in the groove laterally toward the flange 6.- Under some conditions of assembly it is preferable to insert the blade from the side of the rotor instead of from" the periphery and one of the objects of this invention is to provide a simple rim constructiontor the rotor having the flange 7 integralwith the rotor l. lt will be obvious that if the flange 7 were extended above the bottom of the groove 8 the same distance as the flange 6, it would not be possible to insert the bucket shank 11 from the side of the rotor, and in this case the bucket could not be inserted from the periphery because the width of the bucket groove 8 would not permit the enlarged portion of the shank to pass into the grove. The bottom of the groove 8 is wider than the greatest width oi the bucket shank 11, which construction leaves a space between the flange 7 and the lower portion oil the bucket shank into which a pair of wedge members 18 are inserted for the purpose of pressing the lower end of the shank 11 toward the flange 6. The pressure of the wedges opposes any tendency that the bucket might have to rotate about the projection 90f the flange 6 asa pivot. It will be seen thatthe above construction provides a very simple and eflicientmounting for a turbine bucket. It will also be observed that the bucket shanks 11 are held against radial displacement, simply by a projection 12 provided on one side of the bucket shank so that less machining is required in the manutacturing of the buckets.

The flange 7 is undercut and the outer face of the wedge ii; is made to conform to the contourot the undercut side oi the flange 7, so that when the wedges are inserted. and-are driven into holding position they will not be displaced by centrifugal force. In theassembly of the wedges it will be obvious that the outer wedge adjacent the flange 7 will. be inserted first, after which the inner wedge can be driven into place. T his form of mounting for the buckets necessitates a minimum of machining operations and consequently the construction may be produced at a comparatively small cost.

Referring to Fig. 3, wherein a modified form of rotor and bucket mounting is illustrated, 4 is a rotor provided with a rim 5, having peripheral flanges 6 and 7 integral therewith and spaced apart so as to provide a bucket groove 8 between them. The flange 6' is provided with an annular projection 9 for retaining the bucket 10.

The bucket 10 is provided with a shank 11 having a projection 12 at its lower end, which is adapted to fit beneath the annular projection 9 carried by the flange 6. This portion of the construction is pra etieally the same as the construction illustrated in Figs. 1 and 2. The difference of the construction however resides in a different form of flange 7 and a slight difference in the contour of the'free side of the shank 11.

In this construction, the flange 7' does not project above the bottom of the groove 8 as far as the groove 7 of the construction illustrated in Fig. 2. In this case, the wedge member 13' is 'mounted in a groove 14; cut in the outer bottom portion of the groove 8. The lower corner of the shank 11 is cut away at 15, as shown in Fig. 3, and the pressure of thewed-ges is consequently exerted in a direction diagonally upward toward the annular projection 9, thereby exerting a force opposing any force tending to rotate the bucket about the projection 9 as a pivot. This construction can be made as cheaply as the construction previously described and is just as efficient. This construction, however, has the advantage that the buckets 10 may be placed in position by a lateral movement thereof with practically no endwise displacement.

While I have described and illustrated but two embodiments of my invention, it will be apparent to those skilled in the art that various modifica tions, changes, additions, and omissions may be made in the apparatus described and illustrated without departing from the spirit and scope of the invention as set forth by the appended claims.

What I claim is:

1. A turbine mechanism comprising a rotor having a peripheral bucket retaining flange having an overhanging portion, a radially disposed bucket having a shank with a projection adapted to fit under the overhanging portion whereby radial displacement of the shank is prevented, a flange of less diameter for preventing lateral dis placement of the shank and a binding member disposed between the second flange and the shank adapted to hold the shank in engagement with the first flange.

2. A turbine mechanism comprising a rotor having a peripheral bucket retaining flange having an overhanging portion. a radially disposed bucket having a shank with a projection adapted to it under the overhanging portion whereby radial displacement of the shank is prevented, a llange having a periphery of less diameter than the periphery of the rst flange, for preventing lateral displacement of the shank. and a binding member disposed between the serond flange and the shank adapted to hold the shank in engagement with the iii-st flange.

3.:1 turbine mechanism comprising in combination a rotor having a pair of peripheral flanges of different diameters spaced apart to form a bucket groove, the flange of greater diameter being provided with an overhanging portion near the periphery, a radially disposed bucket having a shank provided with a projection adapted to fit under the overhanging portion whereby radial displacement of the bucket is prevented, and a binding member disposed between the free side of the shank and the other flange at a point below the overhanging member for preventing lateral displacement of the bucket shank.

at. A turbine mechanism comprising in combination a. rotor having a pair of peripheral flanges of different diameters spaced apart to form a bucket groove, the flange of greater diameter being provided with an overhanging portion, a. radially disposed bucket having a shank provided, with a projection adapted to fit under the overhanging portion whereby radial displacement of the bucket is prevented, and a wedge member disposed between the other flange and the lower portion of the shank at a point below the overhanging portion, whereby the shank is securely clamped between the saidflange and the overhanging portion.

5. The combination with a. turbine member having an undercut groove, of a bucket having a shank of less width than the groove and having a projection on one side of the shank conforming substantially to the form of the undercut portion of the groove and a binding member disposed between the other side of the groove and the bucket shank adapted to engage the shank adjaramt the lower end thereof, one side of the groove being lower than the other whereby the buckets may be axially inserted in assembling the buckets on the member.

6. In a mounting for turbine blades, a turbine member, an overhanging flange formed on said member, a bucket having a projection formed to fit under the overhanging portionof the flange whereby substantially all of the centrifugal stresses imposed on the bucket are absorbed by the single flange, a groove formed in the face of: the turbine member adjacent the free side of the bucket, and means inserted in said groove for preventing lateral displacement of the bucket.

7. In a mounting for turbine blades, a turbine member, an overhanging flange :tormed on said member, a bucket having a projection formed to fit under the overhanging portion of the flange whereby substantially all 01 the centrifugal stresses imposed on the bucket are absorbed by the single flange, a groove formed in the face oi? the turbine member adjacent the free side of the bucket, and means inserted between said groove and the bucket for preventing lateral displacement of the bucket.

Mounting means for turbine blades, comprising an overhanging flange on the member on which the blades are to be mounted, a blade havlng a shank shaped on.

i one side to lit the overhanging flange, a

groove formed in the member adjacent the free side of the blade shank, and a diagonal key inserted in said groove and bearing against the shank for preventing lateral dis placement thereof, due to the eccentric mounting oi the shank.

In testimony whereof I have hereunto subscribed my name this 20th day of June, 1918.

ALEXANDER T. KASLEY.

Witnesses FLonnNon LEE GAY, E. W. LUNN. 

